The central government has encroached upon the rights of the Delhi assembly by issuing a notification curbing the powers of the AAP government, Deputy Chief Minister Manish Sisodia said on Tuesday."It is encroachment on the rights of the legislative assembly of Delhi. They (central government) have tried to dilute the spirit of the Constitution," Sisodia told a special session of the Delhi assembly.He was referring to the union home ministry notification of May 21 that said the lt. governor has the final say in matters pertaining to services, land, law and order."The assembly must not remain silent on this issue. We all must protest," he added.